Heat exchanger and air-conditioning system

ABSTRACT

Embodiments of the present invention disclose a heat exchanger and an air-conditioning system. The heat exchanger includes heat exchange tubes. The heat exchange tubes include first heat exchange tubes configured to form a first circuit, and second heat exchange tubes configured to form a second circuit. With the heat exchanger according to the embodiments of the present invention, if one of two circuits of a two-circuit air-conditioning system is turned off, a heat exchange efficiency of the heat exchanger can be improved.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims foreign priority benefits under 35 U.S.C. § 119to Chinese Patent Application No. 201811538891.0 filed on Dec. 14, 2018,the content of which is hereby incorporated by reference in itsentirety.

TECHNICAL FIELD

Embodiments of the present invention relate to a heat exchanger and anair-conditioning system.

BACKGROUND

Heat exchangers for two circuits are separate from each other in aconventional air-conditioning system.

SUMMARY

An object of embodiments of the present invention is to provide a heatexchanger and an air-conditioning system. Thereby, for example, if oneof two circuits of a two-circuit air-conditioning system is turned off,at least some of fins for the one circuit may be used for the othercircuit to improve a heat exchange efficiency of the heat exchanger.

Embodiments of the present invention provide a heat exchanger including:heat exchange tubes, wherein the heat exchange tubes include first heatexchange tubes configured to form a first circuit, and second heatexchange tubes configured to form a second circuit.

According to embodiments of the present invention, the first heatexchange tubes have a greater total heat exchange capability than thesecond heat exchange tubes.

According to embodiments of the present invention, the heat exchangerfurther includes: first fins, at least a portion of each of whichextends in a first direction, which are arranged in a row in a seconddirection perpendicular to the first direction, and which are arrangedalternately with the heat exchange tubes.

According to embodiments of the present invention, first heat exchangetube sets each composed of at least one of the first heat exchangetubes, and second heat exchange tube sets each composed of at least oneof the second heat exchange tubes are arranged alternately in the seconddirection.

According to embodiments of the present invention, the first heatexchange tubes, the second heat exchange tubes, and the first fins arealigned, on at least one side in a third direction perpendicular to boththe first direction and the second direction, with one another in thesecond direction.

According to embodiments of the present invention, a number of the firstheat exchange tubes is greater than a number of the second heat exchangetubes, the first heat exchange tube has a greater length than the secondheat exchange tube, the first heat exchange tube has a greater widththan the second heat exchange tube, the first heat exchange tube has agreater thickness than the second heat exchange tube, and/or a totalcross sectional area of internal channels of the first heat exchangetube is greater than a total cross sectional area of internal channelsof the second heat exchange tube.

According to embodiments of the present invention, the heat exchangetubes are arranged in the second direction such that a plurality of samerepeating units are arranged in the second direction, each of therepeating units is composed of a predetermined number of heat exchangetubes, and in each of the repeating units, the first heat exchange tubesand the second heat exchange tubes are arranged alternately in thesecond direction.

According to embodiments of the present invention, each of the repeatingunits is composed of three first heat exchange tubes and two second heatexchange tubes, and each of the two second heat exchange tubes islocated between two adjacent ones of the three first heat exchangetubes; each of the repeating units is composed of two first heatexchange tubes and one second heat exchange tube, and the one secondheat exchange tube is located between the two first heat exchange tubes;or each of the repeating units is composed of four first heat exchangetubes and three second heat exchange tubes, and each of the three secondheat exchange tubes is located between two adjacent ones of the fourfirst heat exchange tubes.

According to embodiments of the present invention, the first heatexchange tube includes: a first heat exchange tube part and a secondheat exchange tube part arranged in a third direction perpendicular toboth the first direction and the second direction; and a connection partconnecting and fluidly communicating the first heat exchange tube partand the second heat exchange tube part with each other, and the firstheat exchange tube part and the second heat exchange tube part are incontact with a same first fin located on one side of the first heatexchange tube part and the second heat exchange tube part in the seconddirection and are in contact with a same first fin located on the otherside of the first heat exchange tube part and the second heat exchangetube part in the second direction.

According to embodiments of the present invention, the heat exchangerfurther includes: first fins, at least a portion of each of whichextends in a first direction, and which are arranged in a row in asecond direction perpendicular to the first direction; and second fins,at least a portion of each of which extends in the first direction, andwhich are arranged in a row in the second direction perpendicular to thefirst direction, wherein the first heat exchange tube includes: a firstheat exchange tube part and a second heat exchange tube part arranged ina third direction perpendicular to both the first direction and thesecond direction; and a connection part connecting and fluidlycommunicating the first heat exchange tube part and the second heatexchange tube part with each other, wherein the first fins and a firstset of heat exchange tubes composed of both the first heat exchange tubeparts and the second heat exchange tubes are arranged alternately in arow in the second direction perpendicular to the first direction, andwherein the second fins and a second set of heat exchange tubes composedof the second heat exchange tube parts are arranged alternately in a rowin the second direction perpendicular to the first direction.

According to embodiments of the present invention, the first heatexchange tube part, the second heat exchange tube part, and theconnection part of the first heat exchange tube are formed by bending asingle heat exchange tube.

According to embodiments of the present invention, the heat exchangerfurther includes: first manifolds respectively disposed at two ends ofeach of the first heat exchange tubes; and second manifolds respectivelydisposed at two ends of each of the second heat exchange tubes.

According to embodiments of the present invention, the first fin has asame size in a third direction perpendicular to both the first directionand the second direction as a bigger one of a portion of the first heatexchange tube in contact with the first fin and a portion of the secondheat exchange tube in contact with the first fin.

According to embodiments of the present invention, the heat exchangerfurther includes: first fins, at least a portion of each of whichextends in a first direction, which are arranged in a row in a seconddirection perpendicular to the first direction, and which are arrangedalternately with the heat exchange tubes, wherein the heat exchanger isbent in an L shape, a U shape, or a C shape when viewed in the seconddirection.

Embodiments of the present invention further provide an air-conditioningsystem including the above heat exchanger.

With the heat exchanger according to the embodiments of the presentinvention, for example, if one of two circuits of a two-circuitair-conditioning system is turned off, at least some of fins for the onecircuit may be used for the other circuit to improve a heat exchangeefficiency of the heat exchanger.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a heat exchanger according toa first embodiment of the present invention;

FIG. 2 is a schematic top view of the heat exchanger according to thefirst embodiment of the present invention, in which flow directions of arefrigerant are indicated by arrows along heat exchange tubes;

FIG. 3 is a schematic top view of a heat exchanger according to a secondembodiment of the present invention, in which flow directions of arefrigerant are indicated by arrows along heat exchange tubes;

FIG. 4 is a schematic partial enlarged view of a heat exchangeraccording to a third embodiment of the present invention;

FIG. 5 is a schematic partial enlarged view of a heat exchangeraccording to a fourth embodiment of the present invention;

FIG. 6 is a schematic perspective view of a heat exchanger according toa fifth embodiment of the present invention;

FIG. 7 is a schematic top view of the heat exchanger according to thefifth embodiment of the present invention;

FIG. 8 is a schematic perspective view of a heat exchanger according toa sixth embodiment of the present invention;

FIG. 9 is a schematic top view of the heat exchanger according to thesixth embodiment of the present invention;

FIG. 10 is a schematic perspective view of a heat exchanger according toa seventh embodiment of the present invention; and

FIG. 11 is a schematic top view of the heat exchanger according to theseventh embodiment of the present invention.

DETAILED DESCRIPTION

An air-conditioning system according to embodiments of the presentinvention includes a heat exchanger. Specifically, the air-conditioningsystem according to the embodiments of the present invention includes acompressor, a heat exchanger as an evaporator, a heat exchanger as acondenser, an expansion valve, and the like. The air-conditioning systemmay include two or more circuits. Each circuit is constituted by aportion of a heat exchanger configured to form this circuit. A pluralityof portions of the heat exchanger respectively configured to form thecircuits are connected in parallel and are independent of one another.

Referring to FIGS. 1 to 11, a heat exchanger 100 according toembodiments of the present invention includes heat exchange tubes 1. Theheat exchange tubes 1 include first heat exchange tubes 1A configured toform a first circuit, and second heat exchange tubes 1B configured toform a second circuit.

According to embodiments of the present invention, the first circuit andthe second circuit may be two circuits connected in parallel and areindependent of each other. The first circuit has a greater heat exchangecapability than the second circuit. For example, the first heat exchangetubes 1A have a greater total heat exchange capability than the secondheat exchange tubes 1B. Referring to FIGS. 1 to 4 and 6 to 11, the heatexchanger 100 according to the embodiments of the present inventionfurther includes first fins 2, at least a portion of each of whichextends in a first direction D1, which are arranged in a row in a seconddirection D2 perpendicular to the first direction D1, and which arearranged alternately with the heat exchange tubes 1. Thereby, forexample, if one of two circuits of a two-circuit air-conditioning systemis turned off, at least some of fins for the one circuit may be used forthe other circuit to improve a heat exchange efficiency of the heatexchanger. In some examples of the present invention, the first heatexchange tubes 1A include a plurality of first heat exchange tube sets,the second heat exchange tubes 1B include a plurality of second heatexchange tube sets, and the plurality of first heat exchange tube setsand the plurality of second heat exchange tube sets are arrangedalternately in the second direction D2. The plurality of first heatexchange tube sets may have the same number or different numbers offirst heat exchange tubes 1A. The plurality of second heat exchange tubesets may have the same number or different numbers of second heatexchange tubes 1B.

Referring to FIGS. 1 to 11, in some embodiments of the presentinvention, a heat exchange capability between the first heat exchangetubes 1A and the fins is greater than a heat exchange capability betweenthe second heat exchange tubes 1B and the fins. In the presentembodiment, a heat exchange capability between the first heat exchangetubes 1A and the first fins 2 is greater than a heat exchange capabilitybetween the second heat exchange tubes 1B and the first fins 2. Forexample, the different heat exchange capabilities of the first heatexchange tubes 1A and the second heat exchange tubes 1B becomeadvantageous when refrigerant circuits and associated compressionsystems have different sizes and capacities to allow for a capacitymodulation and an unloading at different stages.

Referring to FIGS. 1 to 4, in some embodiments of the present invention,the first heat exchange tubes 1A and the second heat exchange tubes 1Bare arranged alternately in the second direction D2. In otherembodiments of the present invention, first heat exchange tube sets eachcomposed of at least one (one, two, three or more) of the first heatexchange tubes 1A, and second heat exchange tube sets each composed ofat least one (one, two, three or more) of the second heat exchange tubes1B are arranged alternately in the second direction D2. In other words,a plurality of first heat exchange tube sets and a plurality of secondheat exchange tube sets are arranged alternately. The heat exchange tube1 may be a flat tube. A number of the first heat exchange tubes 1A isgreater than a number of the second heat exchange tubes 1B, the firstheat exchange tube 1A has a greater length than the second heat exchangetube 1B, the first heat exchange tube 1A has a greater width than thesecond heat exchange tube 1B, the first heat exchange tube 1A has agreater thickness than the second heat exchange tube 1B, and/or a totalcross sectional area of internal channels of the first heat exchangetube 1A is greater than a total cross sectional area of internalchannels of the second heat exchange tube 1B. According to examples ofthe present invention, the first heat exchange tubes 1A, the second heatexchange tubes 1B, and the first fins 2 are aligned, on at least oneside in a third direction D3 perpendicular to both the first directionD1 and the second direction D2, with one another in the second directionD2.

Referring to FIGS. 6 to 11, in some embodiments of the presentinvention, the heat exchange tube 1 may be a flat tube. A number of thefirst heat exchange tubes 1A is greater than a number of the second heatexchange tubes 1B, the first heat exchange tube 1A has a greater widththan the second heat exchange tube 1B, the first heat exchange tube 1Ahas a greater thickness than the second heat exchange tube 1B, and/or atotal cross sectional area of internal channels of the first heatexchange tube 1A is greater than a total cross sectional area ofinternal channels of the second heat exchange tube 1B. According toexamples of the present invention, the first heat exchange tubes 1A, thesecond heat exchange tubes 1B, and the first fins 2 are aligned, on atleast one side in a third direction D3 perpendicular to both the firstdirection D1 and the second direction D2, with one another in the seconddirection D2.

Referring to FIGS. 1 to 4 and 6 to 11, in some embodiments of thepresent invention, the first fin 2 has a same size in the thirddirection D3 perpendicular to both the first direction D1 and the seconddirection D2 as a bigger one of a portion of the first heat exchangetube 1A in contact with the first fin 2 and a portion of the second heatexchange tube 1B in contact with the first fin 2. Thereby, both thefirst heat exchange tube 1A and the second heat exchange tube 1B are incontact with the first fin 2 over their entire sizes (for example theirentire widths) in the third direction D3.

Referring to FIG. 5, in some embodiments of the present invention, theheat exchange tubes 1 are arranged in the second direction D2 such thata plurality of same repeating units 20 are arranged in the seconddirection D2, each of the repeating units 20 is composed of apredetermined number of heat exchange tubes 1, and in each of therepeating units 20, the first heat exchange tubes 1A and the second heatexchange tubes 1B are arranged alternately in the second direction D2.For example, each of the repeating units 20 is composed of three firstheat exchange tubes 1A and two second heat exchange tubes 1B, and eachof the two second heat exchange tubes 1B is located between two adjacentones of the three first heat exchange tubes 1A; each of the repeatingunits 20 is composed of two first heat exchange tubes 1A and one secondheat exchange tube 1B, and the one second heat exchange tube 1B islocated between the two first heat exchange tubes 1A; or each of therepeating units 20 is composed of four first heat exchange tubes 1A andthree second heat exchange tubes 1B, and each of the three second heatexchange tubes 1B is located between two adjacent ones of the four firstheat exchange tubes 1A. The first heat exchange tube 1A and the secondheat exchange tube 1B are heat exchange tubes of the same type.Alternatively, the first heat exchange tube 1A and the second heatexchange tube 1B may be heat exchange tubes of different types. In thisway, for example, a ratio of the heat exchange capability between thefirst heat exchange tubes 1A and the first fins 2 to the heat exchangecapability between the second heat exchange tubes 1B and the first fins2 may be 2:1, 3:2, 4:3, or the like. In this way, a heat exchangecapability of the first fins 2 can be utilized to the utmost extent,while achieving various ratios of the heat exchange capability betweenthe first heat exchange tubes 1A and the first fins 2 to the heatexchange capability between the second heat exchange tubes 1B and thefirst fins 2.

Referring to FIG. 3, in some embodiments of the present invention, thefirst heat exchange tube 1A includes: a first heat exchange tube part1A1 and a second heat exchange tube part 1A2 arranged in the thirddirection D3 perpendicular to both the first direction D1 and the seconddirection D2; and a connection part 1A3 connecting and fluidlycommunicating the first heat exchange tube part 1A1 and the second heatexchange tube part 1A2 with each other. The first heat exchange tubepart 1A1 and the second heat exchange tube part 1A2 are in contact witha same first fin 2 located on one side of the first heat exchange tubepart 1A1 and the second heat exchange tube part 1A2 in the seconddirection D2 and are in contact with a same first fin 2 located on theother side of the first heat exchange tube part 1A1 and the second heatexchange tube part 1A2 in the second direction D2. For example, thefirst heat exchange tube part 1A1, the second heat exchange tube part1A2, and the connection part 1A3 of the first heat exchange tube 1A maybe formed by bending a single heat exchange tube.

In the embodiment shown in FIG. 3, the heat exchanger 100 furtherincludes: first fins 2, at least a portion of each of which extends inthe first direction D1, and which are arranged in a row in the seconddirection D2 perpendicular to the first direction D1; and second fins,at least a portion of each of which extends in the first direction D1,and which are arranged in a row in the second direction D2 perpendicularto the first direction D1. The first heat exchange tube 1A includes: afirst heat exchange tube part 1A1 and a second heat exchange tube part1A2 arranged in the third direction D3 perpendicular to both the firstdirection D1 and the second direction D2; and a connection part 1A3connecting and fluidly communicating the first heat exchange tube part1A1 and the second heat exchange tube part 1A2 with each other. Thefirst fins 2 and a first set of heat exchange tubes 1 composed of boththe first heat exchange tube parts 1A1 and the second heat exchangetubes 1B are arranged alternately in a row in the second direction D2perpendicular to the first direction D1, and the second fins and asecond set of heat exchange tubes 1 composed of the second heat exchangetube parts 1A2 are arranged alternately in a row in the second directionD2 perpendicular to the first direction D1. A height of the second finin the second direction D2 is substantially equal to a distance betweentwo adjacent second heat exchange tube parts 1A2, and is greater than aheight of the first fin 2 in the second direction D2. In other words, inthe present embodiment, the first heat exchange tube 1A has a greaterlength than the second heat exchange tube 1B, thereby achievingdifferent heat exchange capabilities of different circulation circuits.In addition to the achievement of the different heat exchangecapabilities of the different circulation circuits, an installationspace for the heat exchanger is sufficiently utilized. The heatexchanger is obviously superior in heat exchange capability to asingle-row heat exchanger. The first heat exchange tube parts 1A1 andthe second heat exchange tube parts 1A2 may be substantially parallel toone another, and may be substantially parallel to the second heatexchange tubes 1B.

Referring to FIGS. 1 to 3 and 6 to 11, in some embodiments of thepresent invention, the heat exchanger 100 further includes: firstmanifolds 3A respectively disposed at two ends of each of the first heatexchange tubes 1A; and second manifolds 3B respectively disposed at twoends of each of the second heat exchange tubes 1B.

According to embodiments of the present invention, referring to FIGS. 6to 11, the heat exchanger 100 further includes: first fins 2, at least aportion of each of which extends in a first direction D1, which arearranged in a row in a second direction D2 perpendicular to the firstdirection D1, and which are arranged alternately with the heat exchangetubes 1. The heat exchanger 100 is bent in an L shape (FIGS. 6 and 7), aU shape (FIGS. 10 and 11), or a C shape (FIGS. 8 and 9) when viewed inthe second direction D2 (i.e. when viewed in a top view). In addition,the heat exchanger 100 may be bent in any other shape such as a V shape.

According to the embodiments of the present invention, at least some ofthe plurality of first fins 2 are shared by the first heat exchangetubes 1A and the second heat exchange tubes 1B. Therefore, if one of twocircuits of a two-circuit air-conditioning system is turned off, atleast some of the first fins for the one circuit may be used for theother circuit to improve a heat exchange efficiency of the heatexchanger.

According to embodiments of the present invention, referring to FIGS. 1,2 and 4, the first heat exchange tubes 1A and the second heat exchangetubes 1B are arranged alternately in the second direction D2. The heatexchange tube 1 is a flat tube, and the first heat exchange tube 1A hasa greater width than the second heat exchange tube 1B. According toexamples of the present invention, the first heat exchange tubes 1A, thesecond heat exchange tubes 1B, and the first fins 2 are aligned, on atleast one side in a third direction D3 perpendicular to both the firstdirection D1 and the second direction D2, with one another in the seconddirection D2. If a flat tube having a small width which is easily bentis used, a manifold having a small diameter may be used, thereby greatlysaving a cost. In addition, an existing flat tube may be used withoutneeding a flat tube having a new specification. For example, a ratio ofthe width of the first heat exchange tube 1A to the width of the secondheat exchange tube 1B is 2:1. Thereby, the ratio of the heat exchangecapability between the first heat exchange tubes 1A and the first fins 2to the heat exchange capability between the second heat exchange tubes1B and the first fins 2 is 2:1.

According to the embodiments of the present invention, the heat exchangecapacity of the heat exchanger in the part load condition is improved,the heat exchanger can maintain an enough flow rate of a refrigerant forreturning an oil in the part load condition, and in the case where onecircuit fails, the air-conditioning system can continue to operatethrough another circuit.

According to the embodiments of the present invention, the heatexchanger is more compact. In addition, the first heat exchange tubes 1Aand the second heat exchange tubes 1B are arranged alternately to theutmost extent, while achieving heat exchange capabilities of twocirculation circuits which are different in ratio.

In addition, the above embodiments of the present invention may becombined into new embodiments.

While the present disclosure has been illustrated and described withrespect to a particular embodiment thereof, it should be appreciated bythose of ordinary skill in the art that various modifications to thisdisclosure may be made without departing from the spirit and scope ofthe present disclosure.

What is claimed is:
 1. A heat exchanger comprising: heat exchange tubes, wherein the heat exchange tubes comprise first heat exchange tubes configured to form a first circuit, and second heat exchange tubes configured to form a second circuit.
 2. The heat exchanger of claim 1, wherein: the first heat exchange tubes have a greater total heat exchange capability than the second heat exchange tubes.
 3. The heat exchanger of claim 2, further comprising: first fins, at least a portion of each of which extends in a first direction, which are arranged in a row in a second direction perpendicular to the first direction, and which are arranged alternately with the heat exchange tubes.
 4. The heat exchanger of claim 3, wherein: first heat exchange tube sets each composed of at least one of the first heat exchange tubes, and second heat exchange tube sets each composed of at least one of the second heat exchange tubes are arranged alternately in the second direction.
 5. The heat exchanger of claim 3, wherein: the first heat exchange tubes, the second heat exchange tubes, and the first fins are aligned, on at least one side in a third direction perpendicular to both the first direction and the second direction, with one another in the second direction.
 6. The heat exchanger of claim 4, wherein: a number of the first heat exchange tubes is greater than a number of the second heat exchange tubes, the first heat exchange tube has a greater length than the second heat exchange tube, the first heat exchange tube has a greater width than the second heat exchange tube, the first heat exchange tube has a greater thickness than the second heat exchange tube, and/or a total cross sectional area of internal channels of the first heat exchange tube is greater than a total cross sectional area of internal channels of the second heat exchange tube.
 7. The heat exchanger of claim 3, wherein: the heat exchange tubes are arranged in the second direction such that a plurality of same repeating units are arranged in the second direction, each of the repeating units is composed of a predetermined number of heat exchange tubes, and in each of the repeating units, the first heat exchange tubes and the second heat exchange tubes are arranged alternately in the second direction.
 8. The heat exchanger of claim 7, wherein: each of the repeating units is composed of three first heat exchange tubes and two second heat exchange tubes, and each of the two second heat exchange tubes is located between two adjacent ones of the three first heat exchange tubes; each of the repeating units is composed of two first heat exchange tubes and one second heat exchange tube, and the one second heat exchange tube is located between the two first heat exchange tubes; or each of the repeating units is composed of four first heat exchange tubes and three second heat exchange tubes, and each of the three second heat exchange tubes is located between two adjacent ones of the four first heat exchange tubes.
 9. The heat exchanger of claim 3, wherein: the first heat exchange tube comprises: a first heat exchange tube part and a second heat exchange tube part arranged in a third direction perpendicular to both the first direction and the second direction; and a connection part connecting and fluidly communicating the first heat exchange tube part and the second heat exchange tube part with each other, and the first heat exchange tube part and the second heat exchange tube part are in contact with a same first fin located on one side of the first heat exchange tube part and the second heat exchange tube part in the second direction and are in contact with a same first fin located on the other side of the first heat exchange tube part and the second heat exchange tube part in the second direction.
 10. The heat exchanger of claim 2, further comprising: first fins, at least a portion of each of which extends in a first direction, and which are arranged in a row in a second direction perpendicular to the first direction; and second fins, at least a portion of each of which extends in the first direction, and which are arranged in a row in the second direction perpendicular to the first direction, wherein the first heat exchange tube comprises: a first heat exchange tube part and a second heat exchange tube part arranged in a third direction perpendicular to both the first direction and the second direction; and a connection part connecting and fluidly communicating the first heat exchange tube part and the second heat exchange tube part with each other, wherein the first fins and a first set of heat exchange tubes composed of both the first heat exchange tube parts and the second heat exchange tubes are arranged alternately in a row in the second direction perpendicular to the first direction, and wherein the second fins and a second set of heat exchange tubes composed of the second heat exchange tube parts are arranged alternately in a row in the second direction perpendicular to the first direction.
 11. The heat exchanger of claim 9, wherein: the first heat exchange tube part, the second heat exchange tube part, and the connection part of the first heat exchange tube are formed by bending a single heat exchange tube.
 12. The heat exchanger of claim 2, further comprising: first manifolds respectively disposed at two ends of each of the first heat exchange tubes; and second manifolds respectively disposed at two ends of each of the second heat exchange tubes.
 13. The heat exchanger of claim 2, wherein: the first fin has a same size in a third direction perpendicular to both the first direction and the second direction as a bigger one of a portion of the first heat exchange tube in contact with the first fin and a portion of the second heat exchange tube in contact with the first fin.
 14. The heat exchanger of claim 1, further comprising: first fins, at least a portion of each of which extends in a first direction, which are arranged in a row in a second direction perpendicular to the first direction, and which are arranged alternately with the heat exchange tubes, wherein the heat exchanger is bent in an L shape, a U shape, or a C shape when viewed in the second direction.
 15. An air-conditioning system comprising: the heat exchanger of claim
 1. 16. The heat exchanger of claim 5, wherein: a number of the first heat exchange tubes is greater than a number of the second heat exchange tubes, the first heat exchange tube has a greater length than the second heat exchange tube, the first heat exchange tube has a greater width than the second heat exchange tube, the first heat exchange tube has a greater thickness than the second heat exchange tube, and/or a total cross sectional area of internal channels of the first heat exchange tube is greater than a total cross sectional area of internal channels of the second heat exchange tube.
 17. The heat exchanger of claim 10, wherein: the first heat exchange tube part, the second heat exchange tube part, and the connection part of the first heat exchange tube are formed by bending a single heat exchange tube.
 18. The heat exchanger of claim 3, further comprising: first manifolds respectively disposed at two ends of each of the first heat exchange tubes; and second manifolds respectively disposed at two ends of each of the second heat exchange tubes.
 19. The heat exchanger of claim 3, wherein: the first fin has a same size in a third direction perpendicular to both the first direction and the second direction as a bigger one of a portion of the first heat exchange tube in contact with the first fin and a portion of the second heat exchange tube in contact with the first fin.
 20. The heat exchanger of claim 2, further comprising: first fins, at least a portion of each of which extends in a first direction, which are arranged in a row in a second direction perpendicular to the first direction, and which are arranged alternately with the heat exchange tubes, wherein the heat exchanger is bent in an L shape, a U shape, or a C shape when viewed in the second direction. 